Surface cleaning apparatus

ABSTRACT

A surface cleaning apparatus including a water storage container, a steam generator including a heating element, a pump for feeding water from the storage container to the steam generator, and a fluid passage for directing steam from the steam generator to a cleaning head of the apparatus. The apparatus includes a device for blocking the fluid passage which is moveable between blocking and unblocking positions and the apparatus includes a pressure relief valve and there being a further passage connecting the pressure relief valve to the water storage container.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national phase application of International Patent Application No. PCT/GB2014/050360, filed Feb. 7, 2014, which claims priority to U.K. Patent Application No. 1311765.0, filed Jul. 1, 2013, the entire contents of which are hereby incorporated by reference herein.

BACKGROUND

This invention relates to a surface cleaning apparatus. More particularly, this invention relates to an apparatus for cleaning a surface such as a floor or wall which utilises a source of steam.

The use of steam cleaners for cleaning floor and other surfaces is well known. For cleaning floor surfaces, a steam cleaner typically has a cleaning head comprising a body able to be moved, by a user, over the surface to be cleaned, the body being adapted to carry a cleaning element of or including a fabric/textile or other material of a steam permeable absorbent nature. Steam (or very hot water) is emitted from the body and passes through the cleaning element to contact the surface being cleaned, with the effect of loosening dirt from the surface. Dirty water from condensation of the steam on the surface is absorbed by the cleaning element.

The cleaning head, to enable it to be manipulated over the surface being cleaned, may be attached to a wand and steam supplied thereto by way of a hose from a separate steam generator. Alternatively, the wand may itself be provided with a steam generator and supply of water, to form a self-contained steam cleaning device, sometimes referred to as a “stick” or “mop” type of steam cleaner.

The steam generator for such devices typically includes a water storage container (e.g. a tank which a user fills with water), an electric pump (which is controlled by a user operable switch) and a heating element(s). In use, water is fed from the tank to the heating element by the pump, where it is then heated. The resulting steam (or very hot water) then passes from the heating element towards the surface to be cleaned.

SUMMARY

Typically, steam generators for such surface cleaning apparatus do not provide a pressurised source of steam. Rather, the steam falls downwardly under the force of gravity towards the cleaning. When a user no longer requires a source of steam (e.g. they have finished cleaning), the user presses or releases the appropriate switch on the apparatus so as to disconnect the power being supplied to the electric pump. However, water which has already been fed to the heating elements(s) from the storage tank continues to fall towards the cleaning head and is still heated, at least to some degree, by any residual heat in the heating element(s). This “lag” after the cessation of operation of the pump results in steam/very hot water exiting the apparatus at the cleaning head for a period of time thereafter.

According to the present invention, we provide a surface cleaning apparatus including:

-   -   a water storage container;     -   a steam generator including a heating element(s);     -   a pump for feeding water from the storage container to the steam         generator; and     -   a fluid passage for directing steam from the steam generator to         a cleaning head of the apparatus,     -   wherein the apparatus includes a device for blocking the fluid         passage which is moveable between blocking and unblocking         positions and wherein the apparatus includes a pressure relief         valve and there being a further passage connecting the pressure         relief valve to the water storage container.

Further features of the invention are set out in the claims appended hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a surface cleaning apparatus in accordance with the present invention;

FIG. 2 is a illustrative view of the internal components of the surface cleaning apparatus of FIG. 1;

FIG. 3 is an alternative illustrative view of the component parts of the apparatus of FIG. 1; and

FIG. 4 is a front view of a water storage container of the invention.

DETAILED DESCRIPTION

Referring to the figures, these show a surface cleaning apparatus 10 in accordance with an embodiment of the present invention. The apparatus 10 has a floor cleaning head 50 which is pivotally connected to a user graspable handle 11. Connected to the user graspable handle are a water storage container 12 and a housing 18 which houses a steam generator 20, a pump for feeding water from the storage container 12 to the steam generator 20 and a fluid passage 42 connecting a steam generator output to the cleaning head 50. Whilst FIG. 1 shows a surface cleaning apparatus 10 in which is embodied the present invention, it should be appreciated that the invention can be realised in other forms of surface cleaning apparatus. In particular, whilst the handle 11 is pivotally connected to the head 50, it need not be connected in that way (e.g. it could be rigidly connected). In addition, the water storage container 12 and the housing 18 housing may be supported directly on the floor cleaning head 19 rather than attached to the handle 11.

Referring to FIG. 2, this shows an illustrative view of the layout and connection of the internal components of a first embodiment of the present invention. As mentioned previously, the apparatus 10 includes a water storage container 12 for storing a volume of water 13. Typically the water storage container 12 is removable so that it can be filled and/or emptied by a user. It should be appreciated, however, that the water storage container 12 need not necessarily be removable from the remainder of the apparatus 10. In the present embodiment the water storage container 12 is configured such that when a user completely fills the water storage container 12 (as much as they can do so) a volume 14 remains in an upper part of the container 12. The purpose of this volume 14 will be apparent later. The water storage container 12 is open to atmosphere, and includes a suitable aperture (not shown) in the container for that purpose. The aperture is covered by a hydrophobic filter in order to prevent water from escaping from the container 12 (when it is, for example, inverted) but whilst still allowing the container 12 to correctly vent.

The apparatus includes a pump 30 which is fluidly connected, via a water outlet passage tube 15 to the water storage container 12. An outlet 32 from the pump 30 is fluidly connected to a steam generator, which includes a heating element 20 (there may be more than one element) positioned within a housing. As is well known in the art, the pump 30 draws water from the water storage container 12 and feeds the water to the heating element 20. The heating element 20 heats the water to at least close to boiling point, and preferably such that the water turns into steam. The hot water and/or steam exits the steam generator housing via an outlet 22 which is connected to a fluid passage 42 for directing steam to the cleaning head 50. It will be noted that positioned in between the passage 22 and the fluid passage 42 is a device 40 for blocking the passage of fluid therebetween. The blocking device 40 is movable between blocking and unblocking positions, and this particular embodiment is provided by a solenoid valve. The purpose of the valve 20 is to prevent the flow of hot water and/or steam through the passage 42 to the cleaning head 50.

Operation of the apparatus 10 and its internal components is achieved by user operable switches 80, 81 which are shown illustratively in FIG. 2. The switch 81 provides a connection from a power supply (e.g. mains or battery) to the heating element 20. Once activated, the heating element 20 takes a period of time (a number of seconds) to get to operating temperature. The switch 80 provides a connection from a power supply (e.g. mains or battery) to the pump 30 and the valve 40, such that these components are operated at the same time or with a short time period therebetween. It should be appreciated, however, that separate user operable switches could be provided for controlling operation of the pump 30 and valve 40.

The apparatus 10 advantageously includes a pressure relief valve 60 whose input is fluidly connected by a passage 61 to the fluid passage 32. An outlet from the pressure relief valve 60 is connected by a further passage (tube) 62 to the water storage container 12, where it extends a distance into the container 12 (see FIG. 4). It will be seen from FIGS. 2 and 4 that the further passage 62 connecting the pressure relief valve 60 to the water storage container 12 terminates in the volume 14 of the water storage container 12 which does not, in normal use, contain water 13. This is highly advantageous, because any fluid passing through the pressure relief valve 60 and through the passage 62 is able to be taken up by the vacant space 14 in the container 12. In order to ensure that the passage 62 terminates in a volume of air, irrespective of the orientation of the apparatus 10, a free end of the tube 62 is provided with a buoyancy member 63. The buoyancy member 63 ensures that a free end of the tube 62 floats to the top of the water level in the container 12 (whatever its orientation). FIG. 4 also shows the water outlet tube 15 from the container 12. It can be seen that a free end of the tube 15 includes a weighted member 71. The weighted member 71 ensures that the free end of the tube 15 sinks to the bottom of the container 12 (whatever its orientation), so that water can always been drawn therefrom by the pump 30.

In the alternative embodiment shown in FIG. 3, instead of the inlet to the pressure relief valve 60′ being connected to the passage 32 which connects the outlet from the pump 30 to the steam generator, the inlet passage may be connected to a fluid passage 61′ which is connected to the outlet passage 22′ from the steam generator.

The pressure relief valve 60, 60′ is or includes a one-way valve, although it should be appreciated that other types of pressure relief valve could be utilised without departing from the scope of the present invention.

The provision of the pressure relief valve 60, 60′ in the present invention, particularly the location of the outlet from the valve 60, 60′ terminating in the space 14 in the upper part of the container 12 is highly advantageous in the operating of the apparatus 10 by a user.

Operation of the apparatus 10 is as follows. If a user wishes to use the apparatus 10 he/she presses/actuates the switch 80, 80′. This supplies electrical power to the heating element 20, 20′ which heats up to its operational temperature. The switch 80, 80′ also effects the supply of electrical power to the pump 30 (albeit in some cases after a period of time has passed to permit the heating element(s) 20, 20′ to get to operational temperature). The pump 30, 30′ feeds water 13, 13′ from the storage container 12, 12′ to the heating element 20, 20′ which heats the water until it is near boiling point and/or turns to steam. The hot water and/or steam exits the housing containing the heating element 20, 20′, and passes through the valve 40, 40′ to the cleaning head 50, 50′. The operation of the switch 80, 80′ is configured such that the solenoid valve 40, 40′ is moved to an open condition at least as early as the time at which electrical power is supplied to the pump 30, 30′. The user can then move the apparatus 10 over a surface to be cleaned.

When the user decides to finish using the apparatus 10 (or indeed if a power failure to the apparatus 10 is encountered) the switch 80, 80′ (or lack of electrical power to the apparatus 10) stops the pump 30, 30′ from working and removes the supply of electrical power to the heating element 20, 20′. In addition, a lack of electrical power to the solenoid valve 40, 40′ ensures that it moves automatically to its closed position which prevents hot water and/or steam from exiting the apparatus via the cleaning head 50 , 50′.

However, the heating element 20, 20′ will take some time to lose its heat and thus any water contained in the housing for the heating element 20, 20′ will continue to be heated. In prior art apparatus this hot water and/or steam will continue to exit the cleaning head even when the user has decided to stop using the apparatus. However, advantageously, the configuration of the present invention (e.g. the provision of the valve 40, 40′ and the pressure relief valve 60, 60′) ensures that once the user turns the apparatus off at the switch 80, or electrical power supply is lost to the apparatus, no or very little hot water and/or steam exits the apparatus 10 through the cleaning head 50, 50′ as it is prevented from doing so by the valve 40, 40′.

If there is any build up of pressure within the housing containing the heating element 20, 20′, by virtue of the water therein continuing to be heated (even though the heating element 20, 20′ does not have an electrical power supply), above the level to which the pressure relief valve 60 has been set and/or selected, that pressure is vented through the valve 60, 60 and passage 62, 62′ to the water container 12, 12′ (where it can be reused the next time the apparatus 10 is operated by a user). The invention is therefore highly advantageous over prior art apparatus because it ensures that little or no hot water and/or steam continues to be omitted from the cleaning head 50, 50′ once the switch 80, 80′ has been turned “off”. In prior art apparatus hot water and/or steam typically continues to be omitted for a period of time after the apparatus has been turned “off” (typically at least 4 seconds) which can potentially result in injury to the user. Even if injury does not occur, water continues to be emitted from the prior art apparatus, which will be undesirable by the user.

Whilst in the present invention a solenoid valve 40, 40′ is used as the means for blocking the outlet from the housing containing the heating element 20, 20′, it should be appreciated that other types of blocking device could be utilised. What is important is that, preferably, in the event of a lack of electrical power supply to the valve, the valve moves to its closed (i.e. blocking) condition.

When used in this specification and claims, the terms “comprises” and “comprising” and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof. 

1. A surface cleaning apparatus including: a water storage container; a steam generator including a heating element; a pump for feeding water from the storage container to the steam generator; and a fluid passage for directing steam from the steam generator to a cleaning head of the apparatus, wherein the apparatus includes a device for blocking the fluid passage which is moveable between blocking and unblocking positions and wherein the apparatus includes a pressure relief valve and there being a further passage connecting the pressure relief valve to the water storage container.
 2. An apparatus according to claim 1 wherein the further passage connecting the pressure relief valve to the water storage container terminates in an upper part of the water storage container.
 3. An apparatus according to claim 1 wherein the further passage extends into the water storage container and includes a buoyancy member connected to a free end thereof.
 4. An apparatus according to claim 1 wherein the further passage connecting the pressure relief valve to the water storage container terminates in a part of the water storage container which does not contain water.
 5. An apparatus according to claim 1 wherein the pressure relief valve is fluidly connected to a passage which connects an outlet from the pump to an inlet to the steam generator.
 6. An apparatus according to claim 2 wherein the pressure relief valve is fluidly connected to the fluid passage for directing steam from the steam generator to a cleaning head.
 7. An apparatus according to claim 1 wherein the pressure relief valve includes a one-way valve.
 8. An apparatus according to claim 1 wherein the water storage container is open to atmosphere, and preferably includes an aperture which is covered by a hydrophobic filter.
 9. An apparatus according to claim 1 wherein the device for blocking the fluid passage includes a valve.
 10. An apparatus according to claim 9 wherein the valve is actuated by an electrically operated solenoid.
 11. An apparatus according to claim 9 wherein the valve is positioned close to the cleaning head.
 12. An apparatus according to claim 1 wherein the apparatus includes a user operable switch for controlling operation of the blocking device
 13. An apparatus according to claim 1 wherein the apparatus includes a user operable switch for controlling operation of the pump
 14. An apparatus according to claim 1 wherein the apparatus includes a user operable switch for controlling operation of the heating elements.
 15. An apparatus according to claim 1 wherein there is provided one user operable switch for substantially simultaneously controlling the supply of electrical power to the pump, heating element and blocking device.
 16. An apparatus according to claim 15 wherein the switch is moveable between first and second conditions, and wherein, in the first condition, an electrical connection is provided so as to supply power substantially simultaneously to the pump and heating element and the blocking device is moved to an unblocking position.
 17. An apparatus according to claim 15 wherein, in the second condition, the electrical connection is broken so that power is not supplied to the pump and heating element and the blocking device moves to its blocking position.
 18. An apparatus according to claim 1 wherein the blocking device automatically moves to its blocking position when there is no supply of electrical power supply to the apparatus. 19.-20. (canceled) 